[PATCH] tests/core_setmaster: Handle the test even if cards are non-continuous

[Bommu, Krishnaiah]

Old Series : https://patchwork.freedesktop.org/series/136729/

> -----Original Message-----
> From: Bommu, Krishnaiah <krishnaiah.bommu at intel.com>
> Sent: Monday, August 12, 2024 10:55 AM
> To: igt-dev at lists.freedesktop.org
> Cc: Bommu, Krishnaiah <krishnaiah.bommu at intel.com>; Emil Velikov
> <emil.l.velikov at gmail.com>; Ghimiray, Himal Prasad
> <himal.prasad.ghimiray at intel.com>; Kamil Konieczny
> <kamil.konieczny at linux.intel.com>
> Subject: [PATCH] tests/core_setmaster: Handle the test even if cards are non-
> continuous
> 
> Although most of userspace assumes drm cards to be populated continously,
> 
> this assumption may not be always true. After hot unpluging and repluging of
> card
> 
> the card may be non-continous.  To address such scenarios where the cards can
> be non-continous
> 
> modify the tweak_perm function to loop all possible
> cardnumbers(card0-card255) to confirm are they populated or not.
> 
> Problem Description:
> The test fails after running the `core_hotunplug at hot*` subtest, where
> card0 is missing.
> This leads to a failure in the subsequent `master-drop-set-user` test.
> 
> Command sequence for reproducing the issue:
> - Check available cards: `ls /dev/dri/`
> 	- Output: by-path  card0  renderD128
> - Run the test: `# ./core_hotunplug --r hotrebind-lateclose`
> - Check again: ‘ls /dev/dri/’
> 	- Output after failure: by-path  card1  renderD129
> - Run the test: `# ./core_setmaster --r master-drop-set-user`
> 
> This failures on both XE and i915 for above sequence.
> 
> Signed-off-by: Bommu Krishnaiah <krishnaiah.bommu at intel.com>
> Cc: Emil Velikov <emil.l.velikov at gmail.com>
> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> Cc: Kamil Konieczny <kamil.konieczny at linux.intel.com>
> ---
>  tests/core_setmaster.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/core_setmaster.c b/tests/core_setmaster.c index
> 9c2083f66..a2758e2f2 100644
> --- a/tests/core_setmaster.c
> +++ b/tests/core_setmaster.c
> @@ -116,9 +116,10 @@ static unsigned tweak_perm(uint8_t *saved_perm,
> unsigned max_perm, bool save)
>  	for (i = 0; i < max_perm; i++) {
>  		snprintf(path, sizeof(path), "/dev/dri/card%u", i);
> 
> -		/* Existing userspace assumes there's no gaps, do the same. */
> +		/* Userspace cannot always have continuous card0...N due to
> +		 * dynamic unloading or removal of cards */
>  		if (stat(path, &st) != 0)
> -			break;
> +			continue;
> 
>  		if (save) {
>  			/* Save and toggle */
> --
> 2.25.1